A preliminary investigation of lipids and fatty acids composition of Gammarus aequicauda (Crustacea: Amphipoda) and its main food source.

Lipid and fatty acid composition in Gammarus aequicauda from Mar Piccolo (Ionian Sea, Southern Italy) were studied during the spring months. Simultaneously, samples of the macroalgae Chaetomorpha linum were also collected from the same area. During these months Chaetomorpha linum was the main food source of Gammarus aequicauda. The main lipid class were PL and TG both in Gammarus aequicauda and in Chaetomorpha linum with similar concentrations. But PL was the main lipid class in Gammarus aequicauda and TG in Chaetomorpha linum. On average unsaturated fatty acids represent the preponderant part in both G. aequicauda and C. linum. G. aequicauda had an a higher level in MUFA, on the contrary PUFA were the dominant unsaturated fatty acids in C. Linum. Both were characterised by high levels of 18:0, 18:1(n-9), 20:5 (n-3) and 20:4(n-6), in particular C. linum had a high proportion of 14:0 and the ratio of 18:1n 9/18:1n 7 was high.